Durum wheat pasta with high alimentary bran content and process for the production thereof

ABSTRACT

A hard wheat pasta containing bran which has a total fiber content between 30 and 36% and a protein content between 15 and 19%. The pasta preferably has a bran content between 5 and 30% and is produced by a process including the steps of: subjecting hard wheat caryopses to sequential abrasion to substantially remove the bran coating and obtaining a bran fraction (D) which originates from the removal of the aleurone, nucellar and testa layers; adding the bran fraction (D) to a hard wheat semolina substantially free of bran to obtain a mixture containing 5 to 30% of the bran fraction (D); and producing the pasta from said mixture. The disclosure furthermore refers to a hard wheat semolina composition having a fiber content between 30 and 36% and a protein content between 15 and 19% and to a process for its production.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 11/558,590, filed Nov. 10, 2006, and claims priority to European Patent Application No. 05425791.0 filed Nov. 11, 2005, the disclosures of which are hereby incorporated by reference in their entirety.

FIELD OF APPLICATION

The present invention regards the food industry sector and in particular refers to a durum wheat pasta (Triticum turgidum var. durum, Desf.) having a high dietary bran content, to a process for the production thereof, and to a durum wheat semolina having a high dietary fibre content used in such process.

PRIOR ART

Cereals (mainly wheat, rice, corn, barley, oat, rye) are consumed across the world as staple food, because they are a primary source of carbohydrates thanks to the high starch content of the endosperm, which is situated in the central part of the caryopsis (see FIG. 1) and represents its major constituent.

With reference to FIG. 1, the structure of the durum wheat caryopsis 101 is briefly reviewed. Going from the outside inwards, there are the following layers composing the bran: four cell layers (longitudinal, transverse, crossed and tubular) which together compose the coating of the fruit or pericarp 102 (3-6% in weight of the total weight of the caryopsis), and then testa 103, nucellar layer (or hyaline layer) 104 and aleurone 105, which together form the coat of the seed (1,2,3). The inner part is composed of the endosperm 106 and germ 107.

The aleuronic layer, which makes up 5-7% in weight of the total weight of the caryopsis, is composed of a layer of polygonal cells of large size in contact with the endosperm (1, 2).

Semolina is the main product of the durum wheat milling process, the primary objective of which is the achievement of a final product with a high degree of purity (sifted). It is composed of the starchy, innermost parts of the caryopsis (endosperm) following separation from the outermost parts (the bran, which composes about 15% of the total content of the caryopsis, and the germ, which composes about 3%), traditionally intended for animal feed.

Based on this view, the modern process of industrial milling of durum wheat tends to maximise the efficiency of this separation through a series of many operations (milling, sifting) which permits the separation and removal of the bran from the parts of the endosperm which will make up the final semolina.

During the last decade, the nutritional value of “whole grain” cereal flours, i.e. those including the greatest possible quantity of the starting components of the caryopsis (4,5), and therefore also the bran, has been progressively recognised (6,7) as a fundamental element of a healthy diet aimed at maintaining a good state of health for the human being.

A complex series of micro-nutrients are located in the bran, such as dietary fibres (insoluble and soluble), minerals, lipids, vitamins and a class of components known as “phytochemicals”, having protective activity (anti-oxidant) in cell metabolism and in phenomena linked to ageing (8,9,10,11,12). To date, there have been many studies and demonstrations of the beneficial effect of the daily consumption of whole grain products in relation to different types of pathologies (13-27).

In spite of the better nutritional properties of whole grain flours, their consumption in the form of pasta and bakery products, and their appeal, is currently hampered by the perceived organoleptic difference compared to the corresponding finished products obtained from refined flours.

The available whole grain products are penalised by a number of negative organoleptic elements including appearance (dark colour), texture (rough, heavy), a marked flavour often associated to the development of off-flavours over time (rancid, cardboard), which strongly limit their use.

Because of this, the consumption of whole grain cereals in the form of whole grain pastas or bakery products, even though it is recognised as healthier, is associated to a sense of “dissatisfaction or punishment” from the organoleptic standpoint.

Whole grain flours are conventionally produced in the manner described below.

First, there is the breaking (milling) of the whole caryopses, followed by the separation by sifting of the generated fragments, which may be composed by the endosperm only or by parts of the endosperm together with bran and germ, which are sent to subsequent steps of milling and separation in order to free and separate as much as possible the parts of endosperm from the other components of the caryopsis. In the production of whole grain flour, one proceeds with a recovery of the endosperm parts, together with bran and/or actual bran fractions, which are pooled with the main flow of sifted flour.

The whole grain flours thus obtained therefore contain bran which substantially originates from all layers of the caryopsis external to the endosperm.

Semolina or cereal flour production processes which comprise a preliminary removal step of the outer layers of the caryopsis through process phases involving friction and abrasion, prior to the milling of the caryopses, have been known for many years. As examples please see the patent applications EP 0 295 774, EP 0 373 274 and WO 2004/028694. In this manner, about 75% of the bran is removed, and the subsequent steps of milling and separation from the residual bran are simplified and generally lead to improved semolina yields compared to those obtained with conventional processes.

With the aforementioned more recent processes, two or more bran layers are collected, corresponding to as many steps of friction or abrasion carried out on the caryopses. Of these parts, the first is the richest in cellulosic fibres, since it corresponds to the outermost layers of the caryopsis whereas the latter is the richest in protein, since it contains the innermost bran layers, including part of the aleuronic layer.

The actual whole grain semolinas, and those having a certain content of bran and other dietary fibres available on the market, even when they are obtained by means of one of the aforementioned processes, contain bran which is composed in an undifferentiated manner by all of the outer layers of the caryopsis, possibly previously subjected to further milling treatments in order to reduce the size of the particles, and heat stabilisation treatments in order to forestall oxidative phenomena caused by enzymatic degradations.

Also such whole grain semolina, and above all the products derived from these (pasta shapes, baked products), suffer from the same drawbacks from the organoleptic standpoint highlighted above with reference to those obtained by conventional milling processes.

SUMMARY OF THE INVENTION

The problem underlying the present invention was that of providing a durum wheat pasta with a high content of dietary fibre and preferably such as to be defined whole grain (on the basis of the Italian law, a pasta is defined as whole grain when it has an ash content comprised between 1.40 and 1.80% of the dry weight and a minimum protein content of 11.50% of the dry weight) but with organoleptic characteristics such that it results substantially comparable to those of a semolina pasta.

A similar problem was solved by a durum wheat pasta containing bran having a total fibre content comprised between 30 and 36% in weight of the total weight of the bran and a protein content comprised between 15 and 19% in weight of the total weight of the bran.

Preferably, the pasta according to the invention has a bran content comprised between 5 and 30%, advantageously between 10 and 20%, in weight of its total weight (considering an average humidity content of 12%).

The aforementioned bran mainly contains the aleuronic, nucellar and head layers of the original caryopses.

The pasta according to the present invention is produced by means of a process which comprises the steps of:

subjecting durum wheat caryopses, having an endosperm and a germ enclosed within a multilayer bran coating, the innermost layers of which correspond to the aleurone, nucellar and testa layers, to subsequent process phases involving abrasion in order to substantially remove the bran coating, thereby obtaining various bran fractions, the latter of which originates predominantly from the removal of the aforementioned aleurone, nucellar and testa layers;

adding said latter bran layer to a durum wheat semolina substantially free of bran, in such quantities as to obtain a mixture containing from 5 to 30% of the total mixture weight of said bran layer;

producing the pasta by means of conventional techniques, starting from the aforementioned mixture.

Preferably, the aforementioned durum wheat semolina is obtained by the milling of the caryopses from which the bran coating has been substantially removed, and conveniently such milling step is carried out in the same facility in which the aforementioned process phases involving abrasion take place, continuously joining the flows of the durum wheat semolina and the aforementioned latter bran fraction.

The aforementioned process phases involving abrasion are preferably carried out on caryopses which have been previously wetted with a quantity of water such as to bring their humidity content to at least 15% and then subjected to conditioning.

The aforementioned wetting step of the caryopses is preferably carried out by subjecting the caryopses to intense vibrations of a frequency comprised between 50 and 300 Hz.

The present invention moreover refers to a composition based on durum wheat semolina, characterised in that it contains a bran fraction having a total fibre content comprised between 30 and 36% in weight of the total weight of the bran fraction and a protein content comprised between 15 and 19% in weight of the total weight of the bran fraction.

Preferably, such composition based on durum wheat semolina has a bran content comprised between 5 and 30%, advantageously between 10 and 20%, in weight of its total weight.

The aforementioned bran mainly contains the aleuronic, nucellar and testa layers of the original caryopses.

The durum wheat semolina composition according to the present invention is produced with the process according to annexed claims 13-15.

In a further aspect, the invention also regards bakery products containing a bran with a total fibre content comprised between 30 and 36% in weight of the total weight of the bran and a protein content comprised between 15 and 19% in weight on the total weight of the bran.

Finally, the present invention also refers to the use of a durum wheat bran fraction containing essentially the layers of the original caryopses consisting of the aleurone, nucellar and testa layers in the production of whole grain pasta and/or whole grain bakery products.

The aforementioned durum wheat bran fraction may be utilised in the preparation of bakery products based both on durum wheat semolina and soft wheat flour (for example crackers, croissants, breadsticks etc.).

Such durum wheat bran fraction may be utilised as obtained by the abrasion step of the process according to the invention, without additional heat stabilisation or other treatments and the final products therefrom obtained (pastas, bakery products) exhibit optimal organoleptic properties, which they maintain substantially unaltered throughout their shelf-life.

BRIEF DESCRIPTION OF THE DRAWINGS

In FIG. 1 a durum wheat caryopsis is schematically illustrated.

FIG. 2 is a diagram of a plant for the production of a food composition according to the present invention, according to a first embodiment.

FIG. 3 is a diagram of a plant for the production of a food composition according to the present invention, according to a second embodiment.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with an embodiment of the present invention, the process for the production of a composition based on durum wheat semolina according to the invention involves the wheat caryopses 101 undergoing, prior to their rupture (milling), progressive removal of the bran layers, by subjecting the outer surface of the caryopses to the abrasive action of a plurality of decortication or abrasion machines 108 a, 108 b, 108 c (for example 2 or 3), which a flow of wheat passes in series, one after the other (see FIG. 2).

The decortication or abrasion machines 108 a, 108 b, 108 c comprise a vertical axis rotating shaft, on which the abrasive Carborundum grindstones are mounted. Examples of machines for the decortication apt for use in the present process are provided in the applications EP 0 373 274 and EP 0 335 174. One machine which is commercially available and useful in the present process is the machine model DECO 420R from T.A.E. The wheat, upon entering the upper part of the machine, is pushed toward the outlet situated in the lower part. In this way, the wheat is forced to spread itself in the restricted space between the rotating grindstones and a metallic containment baffle, thus undergoing an abrasive action which causes the removal of the outermost bran layers, which are recovered in the form of powder by suction.

This operation is repeated, for example, three consecutive times, thus permitting the progressive separation of increasingly internal bran layers.

With the first passing, the most superficial bran layers are removed, with the second the intermediate layers and finally with the third passing the innermost layers, those nearest to the endosperm and essentially originating from the aleurone 105, nucellar 104 and testa 103 layers, are removed.

Finally, the caryopses (101) exiting from the third abrasion machine 108 c are fed into a conventional mill 109, in which they are ground, producing a flour S consisting essentially of endosperm.

According to an alternative embodiment, illustrated schematically in FIG. 3, the decortication process is carried out twice, utilising the machines 108 a and 108 b, in the first passing mostly removing the layers outside the testa layer.

For its composition characteristics (high protein level, satisfactory content of fibre, minerals, lipids, vitamins and phytochemicals), the third bran fraction D is particularly desirable so as to be joined, during the milling process, with the aforementioned flour S consisting essentially of endosperm.

An average typical composition of the third bran fraction D obtained by the process of the present invention is shown in the table 1, below.

TABLE 1 Component Unit Value Tolerance Humidity % 10.0 ±1.0 Proteins (N × 5.70) % p/p 17.0 ±2.0 Lipids % p/p 6.0 ±1.0 Ash % p/p 5.8 +0.5 Phosphorus mg/100 g 1000 ±100 Magnesium mg/100 g 400 ±50 Calcium mg/100 g 100 ±20 Total dietary fibre % p/p 34.0 ±4.0 Insoluble dietary fibre % p/p 32.0 ±4.0 Cellulose % p/p 8.0 ±2.0 Soluble dietary fibre % p/p 1.8 ±1.0 B-glucans % p/p 2.7 ±1.0 Vit. E (tocopherol) mg/100 g 3.0 ±0.5 Vit. B1 (thiamine) mg/100 g 1.0 ±0.5 Vit. B2 (riboflavin) mg/100 g 0.5 ±0.1 Vit. B6 (pyridoxine) mg/100 g 0.3 ±0.1 Folic acid μg/100 g 60 ±20 Niacin mg/100 g 20 ±10 Pantothenic acid mg/100 g 1.0 ±0.5 Phytic acid mg/g 45.0 ±5.0

The third decortication fraction D is transported to a doser (for example of the screw-type), and the same is done for the flow of the product S obtained by the milling of the caryopsis from which the bran coating has been removed by the above described abrasion steps. The two dosers converge in a mixer 110, which provides an effective mixing in order to provide a food composition C based on durum wheat semolina according to the invention.

Through the mixing screw and immediately before final storage, the food composition C according to the invention is conveyed towards a sifting system in order to guarantee a uniform particle size and to remove any particles excessively large in size.

The food composition based on durum wheat semolina thus obtained proves to be particularly suitable for the production of finished products such as pastas and baked products, in which the maintenance of the nutritional benefits deriving from the presence of the bran components (fibre, minerals, lipids, vitamins, phytochemicals) is associated with organoleptic characteristics of greater quality compared to pastas obtained by the use of conventional bran, in terms of flavour, colour and structure, and surprisingly similar to those of products obtained with sifted flours, that is, completely free of bran.

The organoleptic characteristics (flavour in particular) are indeed maintained substantially unaltered for the entire shelf-life of the finished product. This is remarkable, particularly considering the fact that the bran fraction of the food composition according to the invention, contrary to the consistent teachings of the prior art, does not undergo any heat stabilisation treatment.

The bran obtained with conventional milling processes is indeed subject to deterioration (rancidity, cardboard taste) even after a short period of time, due to the triggering of oxidation reactions of the lipid components present in the bran, in which there may also be present germ parts, very rich in lipids (1,3,28).

Normally, in the bran obtained in the conventional manner, one tries to contain and prevent this phenomenon by destroying (inactivating) the responsible agents (lipolytic enzymes) through heat (heat treatment), in order to avoid the bran fractions triggering oxidation reactions over time and therefore the production of off-flavour, in the finished products in which they are utilised.

The heat treatment of the bran, in addition to representing an additional cost, if done at excessively high temperatures may lead to a further darkening of the bran, the development of odd flavours (toasted, burnt) and the triggering of chemical degradation (by heat) due to the lipid part (28). On the other hand, by the use of excessively low temperatures, the treatment does not permit blocking of the lipolytic enzymes.

Without wishing to be bound by theory, the particular stability to oxidation of the bran fraction of the food composition according to the present invention compared to the traditional bran may be due to the fact that it is obtained with a process which involves lower mechanical and thermal stress compared to those of the conventional processes.

In addition to having the above mentioned advantages, the bran fraction of the food composition and pasta according to the present invention has the additional advantage, compared to traditional bran, of supplying a greater quantity of important nutrients contained in the aleuronic layer (1,2,11,29). Also the appearance is improved, since it is less dark and more yellow, as instrumentally detectable (on the basis of the chromatic scale CIELAB L*a*b*), in comparison with pastas obtained by the use of conventional bran. This is due to the smaller quantity of pigmented components located in particular in the outermost layers of the bran coating, which are capable of causing a darkening of the final products, such as pasta.

Moreover, the texture of the food composition and pasta according to the present invention is more similar to that of a semolina pasta since a reduced discontinuity is noted in the texture (granulosity), lower than that exhibited by the pastas obtained by the use of conventional bran.

Finally, the progressive application of the abrasive action, ensured by the described decortication or abrasion machines, permits the isolation and the use of a more internal bran fraction and therefore, from a hygienic-sanitary standpoint, the first two decortication passings may be considered as an additional and significant extension of the selection and cleaning steps which constitute the initial part, upstream of any milling process.

The present invention will be further described by reference to two examples, provided here below for illustrative and non-limiting purposes.

Example 1

115 kg of durum wheat previously subjected to conventional cleaning steps were wetted with a quantity of water such as to bring the humidity content of the caryopses to 16.5% and simultaneously subjected to the vibrational stresses caused by a Vibronet® machine, produced by Graf GmbH & Co. KG, Lahnau, Germany (vibrational impulses of the duration of about 10 seconds at a frequency of 75 Hz). After a single conditioning of 5 hours, the caryopses were fed (see FIG. 2) to a first machine 108 a of decortication or abrasion, comprising a vertical axis rotating shaft on which abrasive Carborundum grindstones are mounted, thus obtaining the removal of the outermost bran layers, in the form of powder recovered by suction. Two subsequent passings of the caryopses exiting from the first decorticator 108 a into two other respective decortication machines 108 b and 108 c caused the removal of the intermediate and inner bran layers, again in the powder form.

The caryopses exiting from the third decorticator machine 108 c were subjected to a dynamic air current cooling, prior to being fed to a conventional mill 109 for milling. Here the decorticated caryopses were milled according to the standard working modes for the milling of whole caryopses, obtaining in the end 85 kg of a flour S composed essentially of endosperm with an ash content of 0.77% in weight of the total weight and a protein content of 11.0% in weight of the total weight.

The third powder exiting from the last decorticator 108 c was a bran fraction D characterised by the composition shown in the following table 2.

TABLE 2 Component Unit Value Humidity % 10.1 Proteins (N × 5.70) % p/p 17.5 Lipids % p/p 5.8 Ash % p/p 6.0 Phosphorus mg/100 g 1020 Magnesium mg/100 g 355 Calcium mg/100 g 108 Total dietary fibre % p/p 33.8 Insoluble dietary fibre % p/p 31.9 Cellulose % p/p 7.9 Soluble dietary fibre % p/p 1.7 B-glucans % p/p 2.9 Vit. E (tocopherol) mg/100 g 3.1 Vit. B1 (thiamine) mg/100 g 0.9 Vit. B2 (riboflavin) mg/100 g 0.5 Vit. B6 (pyridoxine) mg/100 g 0.3 Folic acid μg/100 g 50 Niacin mg/100 g 22 Pantothenic acid mg/100 g 1.0 Phytic acid mg/g 42.5

From the pooling of the aforementioned third bran fraction with the flour in a 1:9 weight ratio, a durum whole wheat semolina was obtained having an ash content of 1.30% and a protein content of 11.6%.

A whole grain pasta was prepared according to the present invention with the durum whole wheat semolina thus obtained, using it in the conventional production process of traditional durum wheat semolina pasta in place of the refined durum wheat semolina, by the traditional steps of kneading with water, forming by extrusion and drying to a humidity content of 12.0%.

The pasta thus prepared was subjected to comparison with semolina pasta through the evaluation by 100 regular consumers of pasta (semantic differential and liking assessment test). The pasta according to the present invention obtained an appreciation (flavour, texture) equal to that of semolina-only pasta. In particular, appreciation was revealed for the overall flavour, for the texture and for the fragrance while the absence of acidic or bitter notes was confirmed.

A comparison between the pasta thus prepared and commercial pastas obtained with the use of conventional bran was carried out by subjecting such pastas to the judgement of 88 regular pasta consumers (sequential monadic test). The overall appreciation of the pasta thus prepared was significantly higher, in particular in terms of overall flavour, consistency, appearance and colour (both raw and cooked).

A shelf-life test was conducted in extreme storage conditions (35° C. temperature and 70% relative humidity), so as to accelerate the processes of off-flavours formation. Pasta samples thus stored were periodically evaluated by a trained tasting panel, over a period of four months, during which time neither significant variations of the organoleptic properties nor development of off-flavours were detected.

Example 2

115 kg of durum wheat previously subjected to conventional cleaning steps was wetted with a quantity of water such as to bring the humidity content of the caryopses to 16.5% and simultaneously subjected to the vibrational stresses induced by a Vibronet® machine, (vibrational impulses of the duration of about 10 seconds and at a frequency of 75 Hz). After a single conditioning of 5 hours, the caryopses 101 were fed (see FIG. 3) to a first machine 108 a of decortication or abrasion, comprising a vertical axis rotating shaft on which abrasive Carborundum grindstones are mounted, arranged in such a manner as so to determine the removal of the outermost and intermediate bran layers (substantially up until the innermost layer of the pericarp), in the form of powder recovered by suction. A subsequent passing of the caryopses exiting from the first decorticator into a second decortication machine 108 b caused the removal of the innermost bran layers, again in the powder form.

The caryopses exiting the second decorticator machine 108 b were subjected to a dynamic air current cooling, prior to being fed to a conventional mill 109 for milling. Here the decorticated caryopses were milled according to the standard working modes for the milling of whole caryopses, obtaining in the end 84 kg of a flour consisting essentially of endosperm with an ash content of 0.75% in weight of the total weight and a protein content of 11.8% in weight of the total weight.

The powder exiting from the second decorticator was a bran fraction D characterised by the composition shown in table 3 below.

TABLE 3 Componente Unit Value Humidity % 10.2 Proteins (N × 5.70) % p/p 17.3 Lipids % p/p 5.9 Ash % p/p 5.8 Phosphorus mg/100 g 1010 Magnesium mg/100 g 365 Calcium mg/100 g 110 Total dietary fibre % p/p 34.8 Insoluble dietary fibre % p/p 32.9 Cellulose % p/p 8.0 Soluble dietary fibre % p/p 1.7 B-glucans % p/p 2.7 Vit. E (tocopherol) mg/100 g 3.0 Vit. B1 (thiamine) mg/100 g 0.9 Vit. B2 (riboflavin) mg/100 g 0.5 Vit. B6 (pyridoxine) mg/100 g 0.3 Folic acid μg/100 g 51 Niacin mg/100 g 22 Pantothenic acid mg/100 g 1.0 Phytic acid mg/g 48.0

From the pooling of the aforementioned second bran fraction D with the flour S in a 1:9 weight ratio, a durum whole wheat semolina was obtained having an ash content of 1.26% and a protein content of 12.4%.

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H., Description and     Characterization of Wheat Aleurone, Cereal Foods World, Vol. 49, 5,     September-October, 74-282, 2004 

The invention claimed is:
 1. A durum wheat pasta comprising: a durum wheat semolina; and bran, wherein the bran originates from durum wheat caryopses having a bran coating, wherein the caryopses are subjected to sequential abrasion by a decortication machine that does not utilize a milling action in order to selectively and progressively remove substantially all of the bran coating and to select from the removed bran coating a bran fraction (D) originating from the aleurone, nucellar, and testa layers only of the durum wheat caryopses, such that the bran fraction (D) exhibits stability to oxidation without undergoing heat stabilization treatment, wherein said bran fraction (D) has a total fibre content comprised between thirty and thirty-six percent of the total weight of the bran, and a protein content comprised between fifteen and nineteen percent of the total weight of the bran, wherein the bran fraction (D) is added to the durum wheat semolina in a quantity so as to obtain a mixture containing between five and thirty percent of the bran fraction (D) by weight, and wherein the durum wheat pasta is produced from the mixture of durum wheat semolina and the bran fraction (D).
 2. The durum wheat pasta of claim 1, wherein the durum wheat pasta has a bran content comprised between ten and twenty percent of the total weight of the pasta.
 3. The durum wheat pasta of claim 1, wherein the durum wheat semolina is substantially free of bran prior to the bran fraction (D) being added to the durum wheat semolina.
 4. The durum wheat pasta of claim 1, wherein the caryopses are wetted with a suitable quantity of water to bring a humidity content of the caryopses to at least fifteen percent and are subjected to conditioning prior to being subjected to sequential abrasion using the decortication machine.
 5. The durum wheat pasta of claim 4, wherein the caryopses are subjected to vibrations of a frequency comprised between fifty and three-hundred hertz.
 6. The durum wheat pasta of claim 1, wherein organoleptic characteristics of the durum wheat pasta are maintained substantially unaltered for a shelf-life of the durum wheat pasta.
 7. The durum wheat pasta of claim 1, wherein the caryopses are subject to sequential abrasion three consecutive times.
 8. A method for producing a pasta comprising: subjecting durum wheat caryopses having a bran coating to sequential abrasion by utilizing a decortication machine that does not utilize a milling action; selectively and progressively removing substantially all of the bran coating via the sequential abrasion and selecting from the removed bran coating to obtain a bran fraction (D) originating from the aleurone, nucellar, and testa layers only of the durum wheat caryopses, such that the bran fraction (D) exhibits stability to oxidation without undergoing heat stabilization treatment; adding the bran fraction (D) to a durum wheat semolina quantity so as to obtain a mixture containing between five and thirty percent of the bran fraction (D) by weight; and producing the pasta from the mixture of the bran fraction (D) and the durum wheat semolina.
 9. The method of claim 8, wherein the bran fraction (D) has a total fibre content comprised between thirty and thirty-six percent of the total weight of the bran, and a protein content comprised between fifteen and nineteen percent of the total weight of the bran.
 10. The method of claim 8, wherein the durum wheat semolina is substantially free of bran prior to the bran fraction (D) being added to the durum wheat semolina.
 11. The method of claim 8, wherein organoleptic characteristics of the durum wheat pasta are maintained substantially unaltered for a shelf-life of the durum wheat pasta.
 12. The method of claim 8, wherein the sequential abrasion is carried out three consecutive times.
 13. The method of claim 8, further comprising wetting the caryopses with a quantity of water so as to bring a humidity content of the caryopses to at least fifteen percent prior to being subjected to sequential abrasion using the decortication machine.
 14. The method of claim 13, further comprising subjecting the caryopses to conditioning prior to subjecting the caryopses to sequential abrasion.
 15. The method of claim 13, wherein the wetting step includes subjecting the caryopses to vibrations of a frequency comprised between fifty and three-hundred hertz.
 16. The method of claim 8, wherein the durum wheat pasta has a bran content comprised between ten and twenty percent of the total weight of the pasta. 